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Nickless A, Voysey M, Yu LM. Mixed effects approach to the analysis of the stepped wedge cluster randomised trial - accounting for the confounding effect of time. Trials 2015. [PMCID: PMC4660081 DOI: 10.1186/1745-6215-16-s2-p142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Yu LM, Altman DG. Factors affecting the impact of covariate adjustment for binary outcomes in randomised clinical trials (RCTS): a simulation study. Trials 2015. [PMCID: PMC4660186 DOI: 10.1186/1745-6215-16-s2-p155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Freeman D, Waite F, Startup H, Myers E, Lister R, McInerney J, Harvey AG, Geddes J, Zaiwalla Z, Luengo-Fernandez R, Foster R, Clifton L, Yu LM. Efficacy of cognitive behavioural therapy for sleep improvement in patients with persistent delusions and hallucinations (BEST): a prospective, assessor-blind, randomised controlled pilot trial. Lancet Psychiatry 2015; 2:975-83. [PMID: 26363701 PMCID: PMC4641164 DOI: 10.1016/s2215-0366(15)00314-4] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/10/2015] [Accepted: 07/03/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND Sleep disturbance occurs in most patients with delusions or hallucinations and should be treated as a clinical problem in its own right. However, cognitive behavioural therapy (CBT)-the best evidence-based treatment for insomnia-has not been tested in this patient population. We aimed to pilot procedures for a randomised trial testing CBT for sleep problems in patients with current psychotic experiences, and to provide a preliminary assessment of potential benefit. METHODS We did this prospective, assessor-blind, randomised controlled pilot trial (Better Sleep Trial [BEST]) at two mental health centres in the UK. Patients (aged 18-65 years) with persistent distressing delusions or hallucinations in the context of insomnia and a schizophrenia spectrum diagnosis were randomly assigned (1:1), via a web-based randomisation system with minimisation to balance for sex, insomnia severity, and psychotic experiences, to receive either eight sessions of CBT plus standard care (medication and contact with the local clinical team) or standard care alone. Research assessors were masked to group allocation. Assessment of outcome was done at weeks 0, 12 (post-treatment), and 24 (follow-up). The primary efficacy outcomes were insomnia assessed by the Insomnia Severity Index (ISI) and delusions and hallucinations assessed by the Psychotic Symptoms Rating Scale (PSYRATS) at week 12. We did analysis by intention to treat, with an aim to provide confidence interval estimation of treatment effects. This study is registered with ISRCTN, number 33695128. FINDINGS Between Dec 14, 2012, and May 22, 2013, and Nov 7, 2013, and Aug 26, 2014, we randomly assigned 50 patients to receive CBT plus standard care (n=24) or standard care alone (n=26). The last assessments were completed on Feb 10, 2015. 48 (96%) patients provided follow-up data. 23 (96%) patients offered CBT took up the intervention. Compared with standard care, CBT led to reductions in insomnia in the large effect size range at week 12 (adjusted mean difference 6.1, 95% CI 3.0-9.2, effect size d=1.9). By week 12, nine (41%) of 22 patients receiving CBT and one (4%) of 25 patients receiving standard care alone no longer had insomnia, with ISI scores lower than the cutoff for insomnia. The treatment effect estimation for CBT covered a range from reducing but also increasing delusions (adjusted mean difference 0.3, 95% CI -2.0 to 2.6) and hallucinations (-1.9, -6.5 to 2.7). Three patients, all in the CBT group, had five adverse events, although none were regarded as related to study treatment. INTERPRETATION Our findings show that CBT for insomnia might be highly effective for improving sleep in patients with persistent delusions or hallucinations. A larger, suitably powered phase 3 study is now needed to provide a precise estimate of the effects of CBT for sleep problems, both on sleep and psychotic experiences. FUNDING Research for Patient Benefit Programme, National Institute for Health Research.
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John T, Voysey M, Yu LM, McCarthy N, Baudin M, Richard P, Fiquet A, Kitchin N, Pollard AJ. Immunogenicity of a low-dose diphtheria, tetanus and acellular pertussis combination vaccine with either inactivated or oral polio vaccine compared to standard-dose diphtheria, tetanus, acellular pertussis when used as a pre-school booster in UK children: A 5-year follow-up of a randomised controlled study. Vaccine 2015; 33:4579-85. [PMID: 26165918 DOI: 10.1016/j.vaccine.2015.06.105] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/08/2015] [Accepted: 06/29/2015] [Indexed: 11/29/2022]
Abstract
This serological follow up study assessed the kinetics of antibody response in children who previously participated in a single centre, open-label, randomised controlled trial of low-dose compared to standard-dose diphtheria booster preschool vaccinations in the United Kingdom (UK). Children had previously been randomised to receive one of three combination vaccines: either a combined adsorbed tetanus, low-dose diphtheria, 5-component acellular pertussis and inactivated polio vaccine (IPV) (Tdap-IPV, Repevax(®); Sanofi Pasteur MSD); a combined adsorbed tetanus, low-dose diphtheria and 5-component acellular pertussis vaccine (Tdap, Covaxis(®); Sanofi Pasteur MSD) given concomitantly with oral polio vaccine (OPV); or a combined adsorbed standard-dose diphtheria, tetanus, 2-component acellular pertussis and IPV (DTap-IPV, Tetravac(®); Sanofi Pasteur MSD). Blood samples for the follow-up study were taken at 1, 3 and 5 years after participation in the original trial (median, 5.07 years of age at year 1), and antibody persistence to each vaccine antigen measured against defined serological thresholds of protection. All participants had evidence of immunity to diphtheria with antitoxin concentrations greater than 0.01IU/mL five years after booster vaccination and 75%, 67% and 79% of children who received Tdap-IPV, Tdap+OPV and DTap-IPV, respectively, had protective antitoxin levels greater than 0.1IU/mL. Long lasting protective immune responses to tetanus and polio antigens were also observed in all groups, though polio responses were lower in the sera of those who received OPV. Low-dose diphtheria vaccines provided comparable protection to the standard-dose vaccine and are suitable for use for pre-school booster vaccination.
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Freeman D, Sheaves B, Goodwin GM, Yu LM, Harrison PJ, Emsley R, Bostock S, Foster RG, Wadekar V, Hinds C, Espie CA. Effects of cognitive behavioural therapy for insomnia on the mental health of university students: study protocol for a randomized controlled trial. Trials 2015; 16:236. [PMID: 26016697 PMCID: PMC4448545 DOI: 10.1186/s13063-015-0756-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/13/2015] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Insomnia, defined as repeated difficulties getting or staying asleep, is common in the general population. Such sleep difficulties are a problem in their own right, but increasingly it is being recognised that they may also be a contributory factor in the development of a wide range of mental health problems. Our focus is upon the relationship between insomnia and psychotic experiences, such as paranoia and hallucinations. Psychotic experiences commonly occur in mild forms in the general population and have been linked to disrupted sleep. These psychotic-like experiences raise the risk of development of a clinical disorder. Our aim is to reduce insomnia in a large general population group, and examine the effect on paranoia and hallucinations at the age when mental health problems typically emerge. The primary hypotheses are that cognitive behaviour therapy (CBT) for insomnia will reduce insomnia and also levels of paranoia and hallucinations. The theoretical links will be substantiated by a planned mediation analysis. Improvements in a number of other mental health outcomes are also predicted. METHODS/DESIGN We will carry out a parallel group, randomised controlled trial of 2,614 students with insomnia in universities across the UK. In the Oxford Access for Students Improving Sleep (OASIS) trial, participants will be randomised to digital CBT for insomnia (in addition to treatment as usual) or treatment as usual. Online assessments will take place at zero, three, 10 (post-treatment), and 22 (follow-up) weeks. Primary outcomes are insomnia and psychotic-like experiences (paranoia or hallucinatory experiences) at 10 weeks. Secondary outcomes are levels of mania, depression, anxiety, nightmares, psychological wellbeing, and the development of mental health disorders. All main analyses will be carried out at the end of the last follow-up assessment and will be based on the intention-to-treat principle. The trial is funded by the Wellcome Trust. DISCUSSION This study will be the first large-scale causal test of the relationship between sleep disturbance and psychotic experiences. It will provide evidence concerning the clinical effects of treating insomnia in young adults. TRIAL REGISTRATION This trial was registered with Current Controlled Trials (identifier: ISRCTN61272251 ) on 29 January 2015.
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Ballard C, Thomas A, Gerry S, Yu LM, Aarsland D, Merritt C, Corbett A, Davison C, Sharma N, Khan Z, Creese B, Loughlin P, Bannister C, Burns A, Win SN, Walker Z. A Double-Blind Randomized Placebo-Controlled Withdrawal Trial Comparing Memantine and Antipsychotics for the Long-Term Treatment of Function and Neuropsychiatric Symptoms in People With Alzheimer's Disease (MAIN-AD). J Am Med Dir Assoc 2015; 16:316-22. [DOI: 10.1016/j.jamda.2014.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/03/2014] [Indexed: 11/29/2022]
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McQuaid F, Snape MD, John TM, Kelly S, Robinson H, Yu LM, Toneatto D, D'Agostino D, Dull PM, Pollard AJ. Persistence of specific bactericidal antibodies at 5 years of age after vaccination against serogroup B meningococcus in infancy and at 40 months. CMAJ 2015; 187:E215-E223. [PMID: 25802309 DOI: 10.1503/cmaj.141200] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 03/06/2015] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND The multicomponent serogroup B meningococcal (4CMenB) vaccine induces antibodies against indicator strains of serogroup B meningococcus under various schedules. We investigated the persistence of antibodies in 5-year-old children 18-20 months after their last dose (at about 3.5 years of age). METHODS We assessed 5-year-old children who received the 4CMenB vaccine or a recombinant protein vaccine in a previous randomized trial. We also recruited 50 vaccine-naive 5-year-olds and administered 2 doses of 4CMenB to each child. We measured serum bactericidal antibody titres against 4 indicator strains of serogroup B meningococcus matched to each individual vaccine component and against 4 mismatched strains. RESULTS Of those who received the 4CMenB vaccine at 2, 4, 6, 12 and 40 months (n = 16), the percentage with protective antibody titres (≥ 1:4) at 60 months ranged from 44% to 88% against matched strains and from 13% to 81% against mismatched strains. Loss of protective titres was also observed for those who received the 4CMenB vaccine at 12, 40 and 42 months (n = 5) (80%-100% against matched strains, 60%-100% against mismatched strains) or at 40 and 42 months (n = 29) (31%-100% against matched strains, 41%-81% against mismatched strains). Administering the 4CMenB vaccine to 5-year-old children yielded protective titres against matched strains in 92%-100% and against mismatched strains in 59%-100%. The majority of these children reported injection-site pain (40/50 [80%] after dose 1, 39/46 [85%] after dose 2) and erythema (47/50 [94%] and 40/46 [87%], respectively); rates of fever were low (5/50 [10%] and 2/46 [4%], respectively). INTERPRETATION Waning of immunity by 5 years of age occurred after receipt of the 4CMenB vaccine in infancy, even with an additional booster at 40 months. The 4CMenB vaccine is immunogenic and was fairly well tolerated by 5-year-old children, although injection-site pain was noteworthy. TRIAL REGISTRATION ClinicalTrials.gov, no. NCT01027351.
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Taggart DP, Altman DG, Gray AM, Lees B, Nugara F, Yu LM, Flather M. Effects of on-pump and off-pump surgery in the Arterial Revascularization Trial. Eur J Cardiothorac Surg 2014; 47:1059-65. [PMID: 25217501 DOI: 10.1093/ejcts/ezu349] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 08/01/2014] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The Arterial Revascularization Trial (ART) is a randomized comparison of bilateral internal mammary artery (BIMA) versus single internal mammary artery (SIMA) grafting in coronary artery bypass graft (CABG) surgery and is one of the largest randomized trials of surgery ever conducted. ART is also one of the largest studies of contemporary CABG with a high proportion of off-pump surgeries (41%). The objective of this post hoc analysis was to evaluate the surgical process and 1-year outcomes for surgery performed on-pump compared with off-pump. METHODS ART randomized 3102 patients with multivessel coronary artery disease (CAD) to SIMA or BIMA grafts to determine if BIMA grafts have an additional survival advantage at 10 years. The 1-year interim analysis showed an overall very low mortality and major morbidity rate irrespective of whether the procedure was with an SIMA or BIMA. The surgical process and 1-year outcomes were analysed according to whether surgery was performed on-pump or off-pump. RESULTS Baseline variables were not statistically significantly different between on- and off-pump surgery within each treatment group after taking account of the effects of clustering by individual surgeons. At both 30 days and 1 year, there was a low incidence of death (1.2%, 2.3%), stroke (1.1%, 1.7%), myocardial infarction (MI) (1.4%, 1.9%), repeat revascularization (0.5%, 1.5%) and wound reconstruction (1.2%). A similar average number of grafts were performed with on- and off-pump surgery (median = 3), but the duration of surgery was 20-30 min and ventilation time ∼ 2 h shorter with off-pump surgery. Blood loss and platelet transfusions were lower in the off-pump group, with no difference in the need for balloon pump or renal support. Sternal wound reconstruction was similar with off-pump surgery in the SIMA group (0.5 vs 0.6%) and lower with off-pump surgery in the BIMA group (1.4 vs 2.2%). Repeat revascularization was marginally higher in off-pump patients at 30 days (0.8 vs 0.3%) and at 1 year (1.7 vs 1.3%). CONCLUSIONS The outcomes of contemporary CABG are excellent with low mortality, stroke, myocardial infarction and need for wound reconstruction and repeat revascularization whether performed on-pump or off-pump. CLINICAL TRIAL REGISTRATION Controlled-trials.com (ISRCTN46552265).
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Hopewell S, Collins GS, Boutron I, Yu LM, Cook J, Shanyinde M, Wharton R, Shamseer L, Altman DG. Impact of peer review on reports of randomised trials published in open peer review journals: retrospective before and after study. BMJ 2014; 349:g4145. [PMID: 24986891 PMCID: PMC4077234 DOI: 10.1136/bmj.g4145] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/12/2014] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To investigate the effectiveness of open peer review as a mechanism to improve the reporting of randomised trials published in biomedical journals. DESIGN Retrospective before and after study. SETTING BioMed Central series medical journals. SAMPLE 93 primary reports of randomised trials published in BMC-series medical journals in 2012. MAIN OUTCOME MEASURES Changes to the reporting of methodological aspects of randomised trials in manuscripts after peer review, based on the CONSORT checklist, corresponding peer reviewer reports, the type of changes requested, and the extent to which authors adhered to these requests. RESULTS Of the 93 trial reports, 38% (n=35) did not describe the method of random sequence generation, 54% (n=50) concealment of allocation sequence, 50% (n=46) whether the study was blinded, 34% (n=32) the sample size calculation, 35% (n=33) specification of primary and secondary outcomes, 55% (n=51) results for the primary outcome, and 90% (n=84) details of the trial protocol. The number of changes between manuscript versions was relatively small; most involved adding new information or altering existing information. Most changes requested by peer reviewers had a positive impact on the reporting of the final manuscript--for example, adding or clarifying randomisation and blinding (n=27), sample size (n=15), primary and secondary outcomes (n=16), results for primary or secondary outcomes (n=14), and toning down conclusions to reflect the results (n=27). Some changes requested by peer reviewers, however, had a negative impact, such as adding additional unplanned analyses (n=15). CONCLUSION Peer reviewers fail to detect important deficiencies in reporting of the methods and results of randomised trials. The number of these changes requested by peer reviewers was relatively small. Although most had a positive impact, some were inappropriate and could have a negative impact on reporting in the final publication.
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Hanieh S, Hamaluba M, Kelly DF, Metz JA, Wyres KL, Fisher R, Pradhan R, Shakya D, Shrestha L, Shrestha A, Joshi A, Habens J, Maharjan BD, Thorson S, Bohler E, Yu LM, Kelly S, Plested E, John T, Werno AM, Adhikari N, Murdoch DR, Brueggemann AB, Pollard AJ. Streptococcus pneumoniae carriage prevalence in Nepal: evaluation of a method for delayed transport of samples from remote regions and implications for vaccine implementation. PLoS One 2014; 9:e98739. [PMID: 24905574 PMCID: PMC4048273 DOI: 10.1371/journal.pone.0098739] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 05/07/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Pneumococcal disease is a significant cause of morbidity and mortality in young children in Nepal, and currently available pneumococcal conjugate vaccines offer moderate coverage of invasive disease isolates. METHODS A prevalence study of children aged 1.5 to 24 months in urban and rural Nepal was conducted. In the urban group, nasopharyngeal swabs (NPS) were transported using silica desiccant packages (SDP) with delayed processing (2 weeks), or skim-milk-tryptone-glucose-glycerin (STGG) with immediate processing (within 8 hours). Pneumococcal nasopharyngeal carriage prevalence, serogroup/type distribution and isolate genotypes (as defined by multilocus sequence typing) were determined. RESULTS 1101 children were enrolled into the study: 574 in the urban group and 527 in the rural group. Overall carriage prevalence based on culture from specimens transported and stored in STGG was 58.7% (337/574), compared to 40.9% (235/574) in SDP. There was concordance of detection of pneumococcus in 67% of samples. Using the SDP method, pneumococcal carriage prevalence was higher in the rural population (69.2%; 364/526) compared to the urban population (40.9%; 235/574). Serogroup/type distribution varied with geographical location. Over half of the genotypes identified in both the urban and rural pneumococcal populations were novel. CONCLUSION The combination of delayed culture and transport using SDP underestimates the prevalence of pneumococcal carriage; however, in remote areas, this method could still provide a useful estimate of carriage prevalence and serogroup/type distribution. Vaccine impact is unpredictable in a setting with novel genotypes and limited serotype coverage as described here. Consequently, continued surveillance of pneumococcal isolates from carriage and disease in Nepali children following the planned introduction of pneumococcal conjugate vaccines introduction will be essential.
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Collins GS, de Groot JA, Dutton S, Omar O, Shanyinde M, Tajar A, Voysey M, Wharton R, Yu LM, Moons KG, Altman DG. External validation of multivariable prediction models: a systematic review of methodological conduct and reporting. BMC Med Res Methodol 2014; 14:40. [PMID: 24645774 PMCID: PMC3999945 DOI: 10.1186/1471-2288-14-40] [Citation(s) in RCA: 451] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 03/03/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Before considering whether to use a multivariable (diagnostic or prognostic) prediction model, it is essential that its performance be evaluated in data that were not used to develop the model (referred to as external validation). We critically appraised the methodological conduct and reporting of external validation studies of multivariable prediction models. METHODS We conducted a systematic review of articles describing some form of external validation of one or more multivariable prediction models indexed in PubMed core clinical journals published in 2010. Study data were extracted in duplicate on design, sample size, handling of missing data, reference to the original study developing the prediction models and predictive performance measures. RESULTS 11,826 articles were identified and 78 were included for full review, which described the evaluation of 120 prediction models. in participant data that were not used to develop the model. Thirty-three articles described both the development of a prediction model and an evaluation of its performance on a separate dataset, and 45 articles described only the evaluation of an existing published prediction model on another dataset. Fifty-seven percent of the prediction models were presented and evaluated as simplified scoring systems. Sixteen percent of articles failed to report the number of outcome events in the validation datasets. Fifty-four percent of studies made no explicit mention of missing data. Sixty-seven percent did not report evaluating model calibration whilst most studies evaluated model discrimination. It was often unclear whether the reported performance measures were for the full regression model or for the simplified models. CONCLUSIONS The vast majority of studies describing some form of external validation of a multivariable prediction model were poorly reported with key details frequently not presented. The validation studies were characterised by poor design, inappropriate handling and acknowledgement of missing data and one of the most key performance measures of prediction models i.e. calibration often omitted from the publication. It may therefore not be surprising that an overwhelming majority of developed prediction models are not used in practice, when there is a dearth of well-conducted and clearly reported (external validation) studies describing their performance on independent participant data.
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Trück J, Snape MD, Tatangeli F, Voysey M, Yu LM, Faust SN, Heath PT, Finn A, Pollard AJ. Pneumococcal serotype-specific antibodies persist through early childhood after infant immunization: follow-up from a randomized controlled trial. PLoS One 2014; 9:e91413. [PMID: 24618837 PMCID: PMC3950188 DOI: 10.1371/journal.pone.0091413] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 02/10/2014] [Indexed: 12/01/2022] Open
Abstract
Background In a previous UK multi-center randomized study 278 children received three doses of 7-valent (PCV-7) or 13-valent (PCV-13) pneumococcal conjugate vaccine at 2, 4 and 12 months of age. At 13 months of age, most of these children had pneumococcal serotype-specific IgG concentrations ≥0.35 µg/ml and opsonophagocytic assay (OPA) titers ≥8. Methods Children who had participated in the original study were enrolled again at 3.5 years of age. Persistence of immunity following infant immunization with either PCV-7 or PCV-13 and the immune response to a PCV-13 booster at pre-school age were investigated. Results In total, 108 children were followed-up to the age of 3.5 years and received a PCV-13 booster at this age. At least 76% of children who received PCV-7 or PCV-13 in infancy retained serotype-specific IgG concentrations ≥0.35 µg/ml against each of 5/7 shared serotypes. For serotypes 4 and 18C, persistence was lower at 22–42%. At least 71% of PCV-13 group participants had IgG concentrations ≥0.35 µg/ml against each of 4/6 of the additional PCV-13 serotypes; for serotypes 1 and 3 this proportion was 45% and 52%. In the PCV-7 group these percentages were significantly lower for serotypes 1, 5 and 7F. A pre-school PCV-13 booster was highly immunogenic and resulted in low rates of local and systemic adverse effects. Conclusion Despite some decline in antibody from 13 months of age, these data suggest that a majority of pre-school children maintain protective serotype-specific antibody concentrations following conjugate vaccination at 2, 4 and 12 months of age. Trial Registration ClinicalTrials.gov NCT01095471
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Norheim G, Sadarangani M, Omar O, Yu LM, Mølbak K, Howitz M, Olcén P, Haglund M, van der Ende A, Pollard AJ. Association between population prevalence of smoking and incidence of meningococcal disease in Norway, Sweden, Denmark and the Netherlands between 1975 and 2009: a population-based time series analysis. BMJ Open 2014; 4:e003312. [PMID: 24513866 PMCID: PMC3927814 DOI: 10.1136/bmjopen-2013-003312] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To investigate the relationship between the prevalence of smoking in the population and incidence of invasive meningococcal disease (IMD) among children under 5 years of age. DESIGN Retrospective, longitudinal, observational study. Poisson regression controlled for confounding factors. SETTING Norway, Sweden, Denmark and the Netherlands between 1975 and 2009. POPULATION Total population of approximately 35 million people in these four countries. DATA SOURCES Data were collected from the Ministries of Health, National Statistics Bureaus and other relevant national institutes. RESULTS In Norway, there was a significant positive relationship between the annual prevalence of daily smokers among individuals aged 25-49 years and the incidence of IMD in children under 5 years of age, unadjusted (RR=1.04-1.06, 95% CI 1.02 to 1.07, p<0.001) and after adjustment for time of year (quarter), incidence of influenza-like illness and household crowding (RR=1.05-1.07, 95% CI 1.03 to 1.09, p<0.001). Depending on age group, the risk of IMD increased by 5.2-6.9% per 1% increase in smoking prevalence among individuals aged 25-49 years in adjusted analyses. Using limited datasets from the three other countries, unadjusted analysis showed positive associations between IMD in children related to older smokers in Sweden and the Netherlands and negative associations related to younger smokers in Sweden. However, there were no demonstrable associations between incidence of IMD and prevalence of smoking, after adjustment for the same confounding variables. CONCLUSIONS The reduced incidence of IMD in Norway between 1975 and 2009 may partly be explained by the reduced prevalence of smoking during this period. High-quality surveillance data are required to confirm this in other countries. Strong efforts to reduce smoking in the whole population including targeted campaigns to reduce smoking among adults may have a role to play in the prevention of IMD in children.
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Waddington CS, Darton TC, Jones C, Haworth K, Peters A, John T, Thompson BAV, Kerridge SA, Kingsley RA, Zhou L, Holt KE, Yu LM, Lockhart S, Farrar JJ, Sztein MB, Dougan G, Angus B, Levine MM, Pollard AJ. An outpatient, ambulant-design, controlled human infection model using escalating doses of Salmonella Typhi challenge delivered in sodium bicarbonate solution. Clin Infect Dis 2014; 58:1230-40. [PMID: 24519873 PMCID: PMC3982839 DOI: 10.1093/cid/ciu078] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Oral delivery of escalating-dose Salmonella Typhi (Quailes strain) using sodium bicarbonate buffer solution in an outpatient, ambulant-design human infection study demonstrates safety, requires a lower challenge inoculum than that used in historical studies, and offers a unique insight into host–pathogen interactions. Background. Typhoid fever is a major global health problem, the control of which is hindered by lack of a suitable animal model in which to study Salmonella Typhi infection. Until 1974, a human challenge model advanced understanding of typhoid and was used in vaccine development. We set out to establish a new human challenge model and ascertain the S. Typhi (Quailes strain) inoculum required for an attack rate of 60%–75% in typhoid-naive volunteers when ingested with sodium bicarbonate solution. Methods. Groups of healthy consenting adults ingested escalating dose levels of S. Typhi and were closely monitored in an outpatient setting for 2 weeks. Antibiotic treatment was initiated if typhoid diagnosis occurred (temperature ≥38°C sustained ≥12 hours or bacteremia) or at day 14 in those remaining untreated. Results. Two dose levels (103 or 104 colony-forming units) were required to achieve the primary objective, resulting in attack rates of 55% (11/20) or 65% (13/20), respectively. Challenge was well tolerated; 4 of 40 participants fulfilled prespecified criteria for severe infection. Most diagnoses (87.5%) were confirmed by blood culture, and asymptomatic bacteremia and stool shedding of S. Typhi was also observed. Participants who developed typhoid infection demonstrated serological responses to flagellin and lipopolysaccharide antigens by day 14; however, no anti-Vi antibody responses were detected. Conclusions. Human challenge with a small inoculum of virulent S. Typhi administered in bicarbonate solution can be performed safely using an ambulant-model design to advance understanding of host–pathogen interactions and immunity. This model should expedite development of diagnostics, vaccines, and therapeutics for typhoid control.
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Holt TA, Mant D, Carr A, Gwilym S, Beard D, Toms C, Yu LM, Rees J. Corticosteroid injection for shoulder pain: single-blind randomized pilot trial in primary care. Trials 2013; 14:425. [PMID: 24325987 PMCID: PMC3878869 DOI: 10.1186/1745-6215-14-425] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/18/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Shoulder pain is a very common presentation in primary care. Evidence of benefit for subacromial corticosteroid injection is inconclusive and confined largely to studies with short follow-up. We plan a large, definitive, primary-care-based trial to determine efficacy and safety in patients with rotator cuff tendinopathy, and conducted a pilot trial to explore feasibility. METHODS Six general practitioners (GPs) from Oxfordshire, UK underwent update training in assessing painful shoulders and injecting the subacromial space. Each then recruited patients aged 35 to 74 years from primary care complaining of shoulder pain lasting no more than 6 months. Eligible participants were randomized to receive either methylprednisolone acetate 40 mg with lidocaine 1% (total volume 1 ml), or lidocaine 1% alone (total volume 1 ml), injected into the subacromial space. The participants were blinded to treatment allocation. Feasibility outcomes were rates of recruitment, withdrawal, adherence to the protocol, completeness of follow-up, and success of patient masking. Clinical outcomes were the Oxford Shoulder Score (OSS) at baseline and at 4 and 12 weeks, and responses to three satisfaction questions at 2, 4 and 12 weeks. Outcome data were collected by postal questionnaires. RESULTS A total of 40 participants were randomized (80% of the target 50 participants) over 26 weeks giving an overall recruitment rate of 1.5 participants per week. Rates of follow-up were maintained to a high level for the full 12 weeks. Four participants requested a 'rescue' corticosteroid injection but no patients withdrew. The trial GPs gave high scores for their confidence that the patient had remained blinded to treatment allocation during the procedure. The OSS at 4 and 12 weeks and the responses to the satisfaction questions are reported. CONCLUSIONS It is feasible to recruit participants with shoulder pain in the primary care setting for a blinded, randomized trial of corticosteroid injection. Online randomization of participants from the practice is also feasible, and postal questionnaires provide an effective means of gathering outcome data in this area of study. The lessons learned from this pilot will usefully inform the design of a large, definitive efficacy trial in primary care. TRIAL REGISTRATION Current Clinical Trials ISRCTN82357435.
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Snape MD, Saroey P, John TM, Robinson H, Kelly S, Gossger N, Yu LM, Wang H, Toneatto D, Dull PM, Pollard AJ. Persistence of bactericidal antibodies following early infant vaccination with a serogroup B meningococcal vaccine and immunogenicity of a preschool booster dose. CMAJ 2013; 185:E715-24. [PMID: 24062178 DOI: 10.1503/cmaj.130257] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND The multicomponent serogroup B meningococcal (4CMenB) vaccine was recently licensed for use in Europe. There are currently no data on the persistence of bactericidal antibodies induced by use of this vaccine in infants. Our objective was to evaluate serogroup B-specific bactericidal antibodies in children aged 40-44 months previously vaccinated at 2, 4, 6 and 12 months of age. METHODS Participants given 4 doses of 4CMenB as infants received a fifth dose of the vaccine at 40-44 months of age. Age-matched participants who were MenB vaccine-naive received 4CMenB and formed the control group. We evaluated human complement serum bactericidal activity (hSBA) titres at baseline and 1 month after each dose of 4CMenB. RESULTS Before a booster dose at enrolment, 41%-76% of 17 participants previously vaccinated with 4CMenB in infancy had hSBA titres of 4 or greater against 4 reference strains. Before vaccination in the control group (n = 40) these proportions were similar for strains 44/76-SL (63%) and M10713 (68%) but low for strains NZ98/254 (0%) and 5/99 (3%). A booster dose in the 4CMenB-primed participants generated greater increases in hSBA titres than in controls. INTERPRETATION As has been observed with other meningococcal vaccines, bactericidal antibodies waned after vaccination with 4CMenB administered according to an approved infant vaccination schedule of 2, 4, 6 and 12 months of age, but there was an anamnestic response to a booster dose at 40-44 months of age. If 4CMenB were introduced into routine vaccination schedules, assessment of the need for a booster dose would require data on the impact of these declining titres on vaccine effectiveness. ClinicalTrials.gov, no. NCT01027351.
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Freeman D, Startup H, Myers E, Harvey A, Geddes J, Yu LM, Zaiwalla Z, Luengo-Fernandez R, Foster R, Lister R. The effects of using cognitive behavioural therapy to improve sleep for patients with delusions and hallucinations (the BEST study): study protocol for a randomized controlled trial. Trials 2013; 14:214. [PMID: 23845104 PMCID: PMC3717119 DOI: 10.1186/1745-6215-14-214] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 07/01/2013] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Patients with psychosis frequently report difficulties getting or staying asleep (insomnia). Dissatisfaction with sleep is high. Insomnia should be treated in this group, but typically it is not even assessed. Importantly, recent evidence indicates that insomnia triggers and exacerbates delusions and hallucinations. The clinical implication is that if the insomnia is treated then the psychotic symptoms will significantly lessen. In a case series with 15 patients with persecutory delusions resistant to previous treatment this is exactly what we found: cognitive behavioural therapy for insomnia (CBT-I) led to large reductions in both the insomnia and delusions. The clear next step is a pilot randomized controlled test. The clinical aim is to test whether CBT-I can reduce both insomnia and psychotic symptoms. The trial will inform decisions for a definitive large-scale evaluation. METHODS/DESIGN We will carry out a randomized controlled trial (the Better Sleep Trial, or the BEST study) with 60 patients with distressing delusions or hallucinations in the context of a schizophrenia spectrum diagnosis. Half of the participants will be randomized to receive CBT-I, in addition to their standard treatment, for up to eight sessions over 12 weeks. The other half will continue with treatment as usual. Blind assessments will take place at 0 weeks, 12 weeks (post-treatment) and 24 weeks (follow-up). The primary outcome hypotheses are that CBT-I added to treatment as usual will improve sleep, delusions and hallucinations compared with only treatment as usual. All main analyses will be carried out at the end of the last follow-up assessments and will be based on the intention-to-treat principle. The trial is funded by the NHS National Institute for Health Research (NIHR) Research for Patient Benefit Programme. Data collection will be complete by the end of 2014. DISCUSSION This will be the first controlled test of CBT-I for patients with delusions and hallucinations. It will provide significant evidence for an easily administered intervention that is likely to prove very popular with patients experiencing the difficult-to-treat problems of delusions and hallucinations. TRIAL REGISTRATION Current Controlled Trials ISRCTN 33695128.
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Yates TA, Paranthaman K, Yu LM, Davis E, Lang S, Hackett SJ, Welch SB, Pollard AJ, Snape MD. UK vaccination schedule: persistence of immunity to hepatitis B in children vaccinated after perinatal exposure. Arch Dis Child 2013; 98:429-33. [PMID: 23476003 PMCID: PMC3664378 DOI: 10.1136/archdischild-2012-302153] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To assess persistence of immunity to hepatitis B (HBV) in primary school children vaccinated following perinatal exposure. DESIGN Serological survey. SETTING Five UK sites (Berkshire East, Birmingham, Buckinghamshire, Milton Keynes and Oxfordshire). PARTICIPANTS Children from 3 years 4 months to 10 years of age (mean age 6.2 years), vaccinated against HBV from birth following perinatal exposure. INTERVENTIONS A single booster dose of the paediatric formulation of a recombinant HBV vaccine. MAIN OUTCOME MEASURES Titres of antibody against hepatitis B Surface Antigen (anti-HBs) measured immediately before and 21-35 days after the HBV vaccine booster. RESULTS Prebooster anti-HBs titres were >10 mIU/ml in 84.6% of children (n=26; 95% CI 65.1 to 95.6%). All children (n=25, 95% CI 86.3 to 100%) had titres >100 mIU/ml after the booster. CONCLUSIONS This study of antibody persistence among UK children born to hepatitis B infected women, immunised with a 3-dose infant schedule with a toddler booster suggests sustained immunity through early childhood. These data should prompt further studies to address the need for a preschool booster. TRIAL REGISTRATION Eudract Number 2008-004785-98.
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Rossi VA, Winter B, Rahman NM, Yu LM, Fallon J, Clarenbach CF, Bloch KE, Stradling JR, Kohler M. The effects of Provent on moderate to severe obstructive sleep apnoea during continuous positive airway pressure therapy withdrawal: a randomised controlled trial. Thorax 2013; 68:854-9. [PMID: 23723343 DOI: 10.1136/thoraxjnl-2013-203508] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES The aim of this study was to test the effectiveness of Provent, an expiratory nasal resistance valve, to prevent the recurrence of OSA following CPAP withdrawal. DESIGN Randomised, partially blinded, parallel, placebo-controlled trial. SETTING Outpatient sleep clinics in the UK (Oxford) and Switzerland (Zurich). PARTICIPANTS 67 patients with OSA receiving CPAP were randomised to one of three groups for 2 weeks: continuing CPAP, Provent or placebo Provent. MAIN OUTCOME MEASURES Primary outcomes included for Provent versus placebo Provent, OSA severity (oxygen desaturation index (ODI), apnoea-hypopnoea index (AHI)) and Epworth Sleepiness Scale (ESS) score. Secondary outcomes for Provent versus placebo Provent included ODI from ambulatory pulse oximetry and blood pressure (BP). For CPAP versus Provent, or CPAP versus placebo Provent, secondary outcomes included ODI/AHI, ESS and BP. RESULTS 63 patients were included in the per protocol analysis. OSA recurred in the Provent (ODI 35.8, SD 17.4) and placebo Provent (ODI 28.2, SD 18.3) groups, and there was no significant difference in ODI, AHI and ESS between Provent and placebo Provent at 2 weeks (mean difference ODI -1.0, 95% CI -10.0 to +12.0, p=0.85; AHI +3.2, 95% CI -7.7 to +14.1, p=0.52; and ESS -1.4, 95% CI -4.1 to +1.4, p=0.33). ODI from ambulatory pulse-oximetry and BP at 2 weeks were not different in the Provent versus placebo Provent groups. ODI, AHI and BP, but not ESS, were significantly higher in the Provent and placebo Provent groups compared with CPAP. CONCLUSIONS Provent cannot be recommended as an alternative short-term therapy for patients with moderate to severe OSA already on CPAP. TRIALREGNO NCT01332175.
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Hopewell S, Omar O, Hyde C, Yu LM, Doree C, Murphy MF. A systematic review of the effect of red blood cell transfusion on mortality: evidence from large-scale observational studies published between 2006 and 2010. BMJ Open 2013; 3:bmjopen-2012-002154. [PMID: 23645909 PMCID: PMC3646177 DOI: 10.1136/bmjopen-2012-002154] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE To carry out a systematic review of recently published large-scale observational studies assessing the effects of red blood cell transfusion (RBCT) on mortality, with particular emphasis on the statistical methods used to adjust for confounding. Given the limited number of randomised trials of the efficacy of RBCT, clinicians often use evidence from observational studies. However, confounding factors, for example, individuals receiving blood generally being sicker than those who do not, make their interpretation challenging. DESIGN Systematic review. INFORMATION SOURCES We searched MEDLINE and EMBASE for studies published from 1 January 2006 to 31 December 2010. ELIGIBILITY CRITERIA FOR INCLUDED STUDIES We included prospective cohort, case-control studies or retrospective analyses of databases or disease registers where the effect of risk factors for mortality or survival was examined. Studies must have included more than 1000 participants receiving RBCT for any cause. We assessed the effects of RBCT versus no RBCT and different volumes and age of RBCT. RESULTS -32 studies were included in the review; 23 assessed the effects of RBCT versus no RBCT; 5 assessed different volumes and 4 older versus newer RBCT. There was a considerable variability in the patient populations, study designs and level of statistical adjustment. Overall, most studies showed a higher rate of mortality when comparing patients who received RBCT with those who did not, even when these rates were adjusted for confounding; the majority of these increases were statistically significant. The same pattern was observed in studies where protection from bias was likely to be greater, such as prospective studies. CONCLUSIONS Recent observational studies do show a consistently adverse effect of RBCT on mortality. Whether this is a true effect remains uncertain as it is possible that even the best conducted adjustments cannot completely eliminate the impact of confounding.
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Wu Y, Li X, Liu JH, He YN, Yu LM, Liu WH. ZnO nanomaterials based surface acoustic wave ethanol gas sensor. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2012; 12:6505-6509. [PMID: 22962774 DOI: 10.1166/jnn.2012.5419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
ZnO nanomaterials based surface acoustic wave (SAW) gas sensor has been investigated in ethanol environment at room temperature. The ZnO nanomaterials have been prepared through thermal evaporation of high-purity zinc powder. The as-prepared ZnO nanomaterials have been characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray Diffraction (XRD) techniques. The results indicate that the obtained ZnO nanomaterials, including many types of nanostructures such as nanobelts, nanorods, nanowires as well as nanosheets, are wurtzite with hexagonal structure and well-crystallized. The SAW sensor coated with the nanostructured ZnO materials has been tested in ethanol gas of various concentrations at room temperature. A network analyzer is used to monitor the change of the insertion loss of the SAW sensor when exposed to ethanol gas. The insertion loss of the SAW sensor varies significantly with the change of ethanol concentration. The experimental results manifest that the ZnO nanomaterials based SAW ethanol gas sensor exhibits excellent sensitivity and good short-term reproducibility at room temperature.
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Perrett KP, Jin C, Clutterbuck E, John TM, Winter AP, Kibwana E, Yu LM, Curtis N, Pollard AJ. B cell memory to a serogroup C meningococcal conjugate vaccine in childhood and response to booster: little association with serum IgG antibody. THE JOURNAL OF IMMUNOLOGY 2012; 189:2673-81. [PMID: 22855707 DOI: 10.4049/jimmunol.1200451] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The maintenance of adequate serum Ab levels following immunization has been identified as the most important mechanism for individual long-term protection against rapidly invading encapsulated bacteria. The mechanisms for maintaining adequate serum Ab levels and the relationship between Ag-specific memory B cells and Ab at steady state are poorly understood. We measured the frequency of circulating serogroup C meningococcal (MenC)-specific memory B cells in 250 healthy 6- to 12-y-old children 6 y following MenC conjugate vaccine priming, before a booster of a combined Haemophilus influenzae type b-MenC conjugate vaccine and then 1 wk, 1 mo, and 1 y after the booster. We investigated the relationship between circulating MenC-specific memory B cell frequencies and Ab at baseline and following the booster vaccine. We found very low frequencies of circulating MenC-specific memory B cells at steady state in primary school-aged children and little association with MenC IgG Ab levels. Following vaccination, there were robust memory B cell booster responses that, unlike Ab levels, were not dependent on age at priming with MenC. Measurement of B cell memory in peripheral blood does not predict steady state Ab levels nor the capacity to respond to a booster dose of MenC Ag.
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Abu-Omar Y, Taghavi FJ, Navaratnarajah M, Ali A, Shahir A, Yu LM, Choong CK, Taggart D. Reply to letter: Blood support in coronary bypass surgery. Perfusion 2012; 27:353. [PMID: 22730350 DOI: 10.1177/0267659112438989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Clutterbuck EA, Lazarus R, Yu LM, Bowman J, Bateman EAL, Diggle L, Angus B, Peto TE, Beverley PC, Mant D, Pollard AJ. Pneumococcal conjugate and plain polysaccharide vaccines have divergent effects on antigen-specific B cells. J Infect Dis 2012; 205:1408-16. [PMID: 22457293 PMCID: PMC3324398 DOI: 10.1093/infdis/jis212] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A 23-valent unconjugated pneumococcal polysaccharide vaccine (23vP), routinely administered at the age of 65, has limited effectiveness, and revaccination induces attenuated antibody responses. It is not known whether pneumococcal polysaccharide-protein conjugated vaccines (PCV), although highly effective in infants, offer any immunological advantages over 23vP in adults. METHODS We immunized adults with schedules combining both PCV and 23vP and investigated B-cell responses to establish whether PCV7 (a 7-valent PCV) induced T-dependent responses in adults, to assess the role of memory B cells in 23vP-induced antibody hyporesponsiveness, and to identify the B-cell subtypes involved. RESULTS A single dose of PCV7 induced significant increases in serotype-specific memory B-cell populations in peripheral blood indicating a T-dependent response. Conversely, immunization with 23vP resulted in a decrease in memory B-cell frequency. Furthermore, memory B-cell responses to subsequent immunization with PCV7, when given after 23vP, were attenuated. Notably, B1b cells, a subset important in protecting mice against pneumococci, were also depleted following immunization with 23vP in humans. CONCLUSIONS This study indicates that PCV7 may have an immunological advantage over 23vP in adults and that 23vP-induced depletion of memory and B1b-cell subsets may provide a basis for antibody hyporesponsiveness and the limited effectiveness of 23vP. Clinical Trials Registration. ISRCTN: 78768849.
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Khatami A, Snape MD, Davis E, Layton H, John T, Yu LM, Dull PM, Gill CJ, Odrjlin T, Dobson S, Halperin SA, Langley JM, McNeil SA, Pollard AJ. Persistence of the immune response at 5 years of age following infant immunisation with investigational quadrivalent MenACWY conjugate vaccine formulations. Vaccine 2012; 30:2831-8. [PMID: 22394992 DOI: 10.1016/j.vaccine.2012.02.046] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 01/14/2012] [Accepted: 02/20/2012] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND AIMS Serogroup A, C, W-135 and Y meningococcal (MenACWY) conjugate vaccines are recommended for routine adolescent immunisation in the United States and Canada. We evaluated the persistence of bactericidal antibodies through early childhood, following infant immunisation with varying schedules of MenACWY-CRM(197) vaccine. METHODS UK and Canadian infants were immunised with 2-3 doses of MenACWY-CRM(197) or 2 doses of serogroup C meningococcal (MenC) conjugate vaccine, and either MenACWY-CRM(197), 1/5 dose of MenACWY polysaccharide vaccine or no booster at 12 months. Control groups recruited at 60 months had received country-specific infant doses of MenC conjugate vaccine. hSBA titres were measured in participants at 40 and 60 months of age. RESULTS 382 children were enrolled in 12 groups (22-40 per group). By age 60 months, 3-11% of children primed and boosted with MenACWY-CRM(197) had hSBA titres≥1:8 against serogroup A, 14-45% against serogroup C, 57-85% against serogroup W-135 and 42-71% against serogroup Y. Children primed with MenC and boosted with MenACWY-CRM(197) had similar results, except for serogroup C (59%). In age-matched controls administered MenC vaccine at 2, 3, and 4 months (UK), 2 and 12 months or 12 months only (Canada), percentages with hSBA titres≥1:8 were 0-3%, 29-53%, 34-36% and 10-29% against serogroups A, C, W-135 and Y respectively. CONCLUSIONS Serogroup-specific bactericidal antibody wane following infant immunisation with MenACWY-CRM(197), most markedly against serogroup A. Best persistence against serogroup C is observed with MenC conjugate vaccine priming and MenACWY-CRM(197) at 12 months, compared to schedules using only MenACWY-CRM(197), with the potential for providing broader protection compared to monovalent MenC vaccines alone.
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